During the summer, I noticed that the light for the rear screen was on, and couldn't switch it off. Then it went off. Now that I need it, it won't come on. that's the light on the switch and the screen!!. Is is a push on and off, or is it push and then timer? Am I looking at getting a new switch, fuse or even screen!

It's a toggle switch (i.e. push once for on and again for off) It also has a timer - 20 mins I think - designed to stop you overheating the screen. My advice would be to try the fuse first, and if that doesn't make any difference, it might be screen element, or it might just be the switch itself. Best bet for that might be to get a voltmeter (they cost less than a tenner these days) and see if you can detect any voltage at the switch and screen element terminals. You might have to remove some trim, but it'll still be cheaper than getting a garage to do it...

Sounds like the switch is at fault to me. It should press in and stay in when the screen is on then press again and it comes back out to turn it off. As far as I am aware there is no timer on the Octavia.